Impact of Endoscopic and Histologic Activity on Disease Relapse in Ulcerative Colitis

Endoscopic healing is currently considered the main target in the management of ulcerative colitis (UC). There are conflicting data about the role of histology as a stricter treatment objective. We aim at evaluating the additional benefit of histologic remission over endoscopic remission.

We performed a prospective observational study at the McGill University Health Center. We enrolled adult patients with UC in clinical remission for at least 3 months undergoing a colonoscopy. Endoscopic disease activity was based on the Mayo endoscopic score. Rectal biopsies were obtained, and the histologic activity was evaluated using the Geboes score (active disease defined as Geboes score ≥ 3.1) with the addition of assessing the presence of basal plasmacytosis. Patients were followed up for 12 months for disease relapse defined as a partial Mayo score of > 2. At the time of relapse or end of follow-up, all patients underwent repeat endoscopic evaluation. The primary end point was clinical relapse.

Two hundred fifty-three patients were included. The presence of basal plasmacytosis was associated with relapse (adjusted odd ratio = 2.07, 95% confidence interval [CI] 1.06-4.18, P = 0.042). Time to clinical relapse was significantly higher for patients with Mayo endoscopic score > 0 with adjusted hazard ratio = 2.65, 95% CI 1.31-5.39, and P = 0.007. Time to clinical relapse was not significantly higher for Geboes score ≥ 3.1 with adjusted hazard ratio = 1.29, 95% CI 0.67-2.49, and P = 0.45.

Active histologic disease did not affect time to clinical relapse in patients with UC who achieved endoscopic remission while the presence of basal plasmacytosis is associated with relapse.